Compound for thermaphores.



DI G R E B N E N 0 R c c CMPOUND FUR THEBMAPHORES.

(Application filed Feb. 4, 1899.)

(No Model.)

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NiTn STATES CARL CRONENBERG, OF BERLIN, GERMANY. y,

coiviPouNoroR THERMAPHoRl-z's.

sPncrFrcAcrIoN forming part of Letters Patent No. 683,851, atea october 1, 1901.

Application filed February 4, 1899.

To @ZZ whom t mfc/y concern:

Be it known that I, CARL CRONENBERG, merchant, a subject of the Emperor of Germany, residing at 187 Friedrichstrasse, Berlin, in the Kingdom of Prussia and Empire of Germany, have invented certain new and useful Improvements in Compounds for Ther maphores, of which the following is a full, clear, and exact description.

This invention relates to improvements in compounds fo'r thermaphores or that class of apparatus in which heat is generated by melting sodium acetate.

In the accompanying drawing I have shown in vertical section a form of apparatus or thermaphore in which mycom pound is adapted for use.

In the employment of such apparatus when a certain quantity of heat has to be maintained for a long time by the salts which have been previously melted and are to be again crystallized several points have to be observed in order to insure satisfactory results. For instance, it is necessary after the melting of the crystalline substance that the recrystallization-that is to say, the giving of the heat-can be set in progress at the time when required for use, and that, further, for the protection of the sides of the vessel and for other practical reasons the crystallized material should not settle down into a solid body, but rather assume the form of a pulp or semiliquid. The first of these objects is attained as follows: The more or less concentrated solution of salts, chiefly consisting, as is known, of acetate of sodium, is inclosed in a hollow receptacle the opening of which is closed by means of an air-tight screw-cover Z, having in its under side a pointed rod which projects into the crystalline substance. As the vessel is not entirely filled, there is a fr ee space of about ten millimeters in height above the body of the salts. The advantage of this arrangement is that in the recrystallization of the salts the crystalline material takes on a form resembling sand in consistency and has space for expansion, whereby injury to the vessel is avoided.

If the heating Serial No. 704,521. (No specimens.)

vessel B, which may be of any desired construction, be heated for the purpose of melt- 5o ing the salts, the very slow and first recrystallization which takes place after the removal from the source of heat may be employed for heating any desired substance contained in a vessel inclosed in said hollow receptacle. After the cooling, which proceeds very slowly, a complete recrystalliz'ation of the salts does not set in without spe# cial action from without. Even an ordinary shock or vibration is without eect on the 6o saltsolution contained in the particular ves; sel. The recrystallization or giving O of the heat begins, however, if the hitherto closed screw-cover be opened and thereby the point of the rod which is in the liquid be partiallyV withdrawn therefrom. The complete crystallizing of the salts employed oc' curs immediately, and the heat thereby set free can be applied for various purposes.

For the employment of this kind of heat- 7o preserving apparatus with metal or sheetmetal vessels it is of importance for the protection of the sides and of still greater importance in the employment of this heat-preserving apparatus with flexible sides that the body of salts be not reduced to a compact form in crystallizing, but that it should have a soft pliable texture. For attaining this 0bject a certain quantity of glycerin is added to the solution of salts, through the addition 8o of which the body of salts in crystallizing is prevented from settling down in compact form, but assumes the consistency of moist sand, which is yielding and will conform to the shape of th'e container or vessel. 85

What I claim, and desire to secure by Letters Patent, is-

A compound for thermaphores, composed of acetate of soda and glycerin.

In Witness whereof I subscribe my signan 9o ture in presence of two witnesses.

CARL CRONENBERG.

Witnesses:

ERWIN L. GoLDscHMIDT, HENRY HASPER. 

